Services & Resources / Wolfram Forums
MathGroup Archive
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2002

[Date Index] [Thread Index] [Author Index]

Search the Archive

Changing delayed formula

  • To: mathgroup at
  • Subject: [mg35461] Changing delayed formula
  • From: "Julio Vera" <jvera at>
  • Date: Sat, 13 Jul 2002 03:49:01 -0400 (EDT)
  • Sender: owner-wri-mathgroup at


I have a list of lists. it's length (the number of sublists it 
contains) varies.

In[1]:= des={{11,12,13,14},{21,22,23},{31,32},{41,42,43,44,45}}

Out[1]:= {{11,12,13,14},{21,22,23},{31,32},{41,42,43,44,45}}

The length of each of the sublists is arbitrary, too. So I have this 
list of lengths.

In[2]:= elems=Flatten[Table[Dimensions[des[[i]]],{i,Length[des]}]]

Out[2]:= {4,3,2,5}

I want to obtain the list of all combinations of one element of each 
sublist, bounded by &&. This will be a list of 120 elements, each of 
them with 4 components. I define a delayed formula, and apply Array to 
it (the characters printed as bold are subscripts in the Mathematica 


In[4]:= combi=Flatten[Array[condLength[des],elems]]



Since the length of des varies, I would have to define cond each time. 
For instance:


I would like to make a definition for cond that would adapt to these 
changes automatically.

I arrived to this solution, which is not rejected by Mathematica, but 
does not work, either.

In[5]:= d[a_,b_]:=des[[a,b<>"_"]]

In[6]:= Unprotect[ReplaceAll]

Out[6]:= {ReplaceAll}


In fact, I quit the kernel and rerun all the cells except the one 
written here as In[3]. If not, the definition for cond4 remains as it 
was. I was not able to clear cond4 individually.

Thanks very much for anything you can suggest.

Best regards,

Julio Vera

  • Prev by Date: RE: Re: symbolic and indefinite differentiation
  • Next by Date: Re: Mathematica Animation Problem
  • Previous by thread: Re: How to pick all terms which have are multiplied with a factor, e.g., 2
  • Next by thread: Re: Changing delayed formula